728
FXAK67 PAJK 082142 CCA
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
959 AM AKDT SAT AUG 8 2026
UPDATE
UPDATED AVIATION SECTION FOR 18Z TAFS
SYNOPSIS
KEY MESSAGES:
-NO MAJOR WEATHER CONCERNS EXPECTED INTO THE WEEKEND. PERIODS OF
LIGHT RAIN AND OVERCAST SKIES CONTINUE THROUGH SUNDAY. HIGHS
REACH INTO THE MID TO UPPER 60S SATURDAY, WARMER TEMPERATURES
EXPECTED SUNDAY.
-MARINE LAYER LOW CLOUDS WILL PERSIST OVER THE EASTERN GULF AND
INNER CHANNELS THROUGH THE WEEKEND.
-SUICIDE BASIN GLACIER DAMMED LAKE CONTINUES TO FILL, AT THIS TIME IT
IS EXPECTED TO BE FULL SOMETIME AUGUST 10TH OR 11TH. IN THE
PAST, IT HAS TAKEN UP TO 6 DAYS FOR THE MAIN FLOODING EVENT TO
START AFTER THE BASIN IS FULL. VISIT WEATHER.GOV/AJK/SUICIDEBASIN
FOR MORE INFORMATION.
SHORT TERM
/ THROUGH MONDAY NIGHT / PRECIPITATION CHANCES
LINGER ACROSS THE NORTHERN PANHANDLE THIS MORNING AS A BAND OF
RAIN MOVES NORTH ACROSS AND OUT OF THE AREA BY MID MORNING.
SATURDAY IS EXPECTED TO BE MAINLY DRY WITH MOSTLY CLOUDY SKIES AS
THE LOW CLOUDS FROM OVERNIGHT LIFT WITH DAYTIME HEATING.
TEMPERATURES ARE EXPECTED TO BE IN THE LOW TO MID 60S DUE TO THE
LACK OF DIRECT DAYTIME HEATING. THIS TREND OF AN OVERNIGHT
INCREASE IN PRECIPITATION CHANCES, ESPECIALLY IN THE NORTHERN
PANHANDLE, IS EXPECTED TO CONTINUE SATURDAY AND SUNDAY NIGHT WITH
DRYER CONDITIONS THROUGH THE FOLLOWING DAYTIME HOURS. AN AREA OF
DRYER AIR IN THE MID-LEVELS OF THE ATMOSPHERE IS EXPECTED MAKE ITS
WAY ACROSS THE SOUTHERN PANHANDLE SUNDAY, BRINGING THE INCREASED
LIKELIHOOD OF CLEARER SKIES BY THE END OF THE DAY.
LONG TERM
/TUESDAY THROUGH THURSDAY NIGHT/
ENSEMBLE MODELS HAVE REACHED GREATER CONSENSUS ON THE TRACK OF
THE MAIN SYSTEM FOR NEXT WEEK. A WEAK UPPER-LEVEL TROUGH IS
EXPECTED TO MOVE OVER THE AREA MONDAY AND TUESDAY, BRINGING LIGHT,
AND GENERALLY UNIMPACTFUL PRECIPITATION. A MID-LEVEL LOW WILL
SUPPLY VORTICITY TO THE REGION MONDAY AND TUESDAY, AMPLIFYING
ANTICIPATED RAIN SHOWERS BEFORE TAPERING OFF AS HIGH PRESSURE
BUILDS ON WEDNESDAY. A SIGNIFICANT UPPER-LEVEL RIDGE WILL BUILD ON
WEDNESDAY, WHILE THE LOW-LEVEL RIDGE STRENGTHENS EARLY NEXT WEEK
AS THE LOW TRACKS SOUTH AND EAST TOWARD THE AOR. HIGH PRESSURE
REMAINS THE DOMINANT FEATURE, KEEPING THE MAIN LOW TO THE WEST AS
IT TRACKS OVER THE ALEUTIANS, DIGS SOUTH, AND MOVES INTO THE KENAI
PENINSULA. WHILE THE CURRENT EXPECTATION IS FOR THE MAIN FRONTAL
PRECIPITATION TO PUSH THROUGH ON TUESDAY WITH A MEAN 24 HOUR
ACCUMULATION OF 0.25” (SUPPORTED BY THE 75TH PERCENTILE NBM AND
GEFS/EC ENSEMBLE AGREEMENT), THERE REMAINS A RISK THAT IF THE LOW
SHIFTS FURTHER EAST, YAKUTAT AND SURROUNDING AREAS COULD
EXPERIENCE HEAVIER BANDS OF RAIN SHOWERS BETWEEN THURSDAY AND
FRIDAY. FOR NOW, THE EXPECTED TRACK WILL KEEP THE NORTHEAST GULF
COAST UNDER LIGHT RAIN SHOWERS, BUT NOTHING UNSEASONABLE. AFTER
THE MIDWEEK SYSTEM PUSHES THROUGH, THE CENTRAL AND SOUTHERN
PANHANDLE ARE EXPECTED TO SEE CLEARER SKIES, AND THEREFORE WARMER
TEMPERATURES. CURRENT THINKING PUTS INLAND AND SOUTHERN AREAS WITH
HIGHS IN THE LOW 70S FOR WEDNESDAY AND THURSDAY.
AVIATION
AN UPPER LEVEL LOW OFFSHORE OF PRINCE OF WALES ISLAND CONTINUES TO
ROTATE, BRINGING MOISTURE INTO THE CENTRAL AND NORTHERN PANHANDLE.
OUT IN THE GULF, HIGH PRESSURE AND MARINE CLOUDS ARE CONTRIBUTING
TO THE IFR AND MVFR CONDITIONS CURRENTLY BEING SEEN. MVFR TO
LOCALIZED IFR CONDITIONS ARE EXPECTED TO CONTINUE FOR THE ICY
STRAIT CORRIDOR, PARTICULARLY NEAR WEST FACING MOUNTAINS, AND ALSO
IN THE NORTHERN INNER CHANNELS. AS DAYTIME HEATING CONTINUES AND
WINDS PICK UP SLIGHTLY TO AROUND 10 KNOTS, CLOUD DECKS ARE
EXPECTED TO RAISE TO HIGH MVFR TO VFR CONDITIONS. EXPECTING TO SEE
THESE LOW CLOUDS RETURN TONIGHT, WITH OVERALL LIGHT WINDS.
MARINE
OUTSIDE: A 1023MB HIGH PRESSURE CONTINUES TO TAKE RESIDENCE OVER
THE GULF THROUGH SUNDAY, KEEPING OVERCAST SKIES WITH LIGHT AND
VARIABLE WINDS ALONG THE COAST AND OUTER WATERS, 10KTS OR LESS.
WAVE HEIGHTS REMAIN LARGELY BENIGN THROUGH THE EARLY WEEK, AROUND
4FT OR LESS ALONG THE COAST. MAIN MARINE CONCERN FOR OUTER AND
COASTAL WATERS WILL BE NIGHTLY RETURN OF MARINE LAYER, DROPPING
VISIBILITIES AS LOW AS ONE QUARTER MILE EACH MORNING. IF PATTERN
SERVES LIKE THE PREVIOUS FEW DAYS, CAPE SPENCER NEAR ENTRANCE TO
CROSS SOUND AND NORTHWARD TO THE FAIRWEATHER GROUNDS WILL LIKELY
SEE SOME AREAS OF PATCHY DENSE FOG SATURDAY MORNING AND ONCE AGAIN
SUNDAY MORNING.
INSIDE: CONDITIONS ACROSS THE INNER WATERS REMAIN CALM THIS
MORNING, WITH OVERCAST SKIES AND LIGHT RAIN WITH WINDS LARGELY
10 KTS OR LESS. NOT SEEING A REAL DRIVING FORCE FOR WINDS THROUGH
SATURDAY, OUTSIDE OF THE USUAL DAILY SEA BREEZE. AS PER USUAL,
WILL LIKELY SEE STRONGEST WINDS IN LYNN CANAL NORTHWARD TO TAIYA
INLET WITH SUSTAINED SOUTHERLY WINDS 10 TO 15KTS, POTENTIALLY A
GUST UP TO 20KTS. WAVE HEIGHTS REMAIN 4 FEET OR LESS THROUGH EARLY
WEEK.
HYDROLOGY
SUICIDE BASIN GLACIER DAMMED LAKE CONTINUES TO FILL.
THE POOL ELEVATION AS OF 9 PM FRIDAY WAS AT 1343 FT WITH A RATE
OF RISE OF AROUND 2 FT OVER THE LAST FEW DAYS. THE OVERFLOW
CHANNEL IS AT AN ELEVATION OF AROUND 1350 FT SO THE LAKE HAS
ANOTHER 7 FT TO RISE BEFORE IT STARTS TO OVERFLOW ACROSS THE SIDE
OF THE GLACIER. WITH THE RATE OF RISE OVER THE LAST FEW DAYS AND
WEATHER CONDITIONS EXPECTED TO REMAIN MOSTLY CONSISTENT WITH CLOUD
COVER AND NEAR NORMAL TEMPERATURES THE LAKE IS EXPECTED TO LIKELY
BECOME FULL AROUND AUGUST 10TH OR 11TH. ONCE THAT POINT IS
REACHED, IN THE PAST IT HAS TAKEN UP TO 6 DAYS BEFORE THE LAKE
STARTS RELEASING.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE.
MARINE...NONE.
SHORT TERM...AGP
LONG TERM...BAS
AVIATION...NC
MARINE...NM
VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page